SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd951abd5d3e93d4001130cd4640f4b725f4b28e8a675adcd64e7f0e5c1fd56ff' 
  AND token = 'WvoWoubobeg+BG6HC+KCj8n5LUBmxe/hyHdwMeSuUYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}